:root {
  --bg: #f0f2f5;
  --surface: #ffffff;
  --text: #1a1d21;
  --text-dim: #5f6368;
  --accent: #1d4ed8;
  --accent-soft: rgba(29, 78, 216, 0.08);
  --accent-hover: #2563eb;
  --elementary: #15803d;
  --middle: #b45309;
  --high: #1d4ed8;
  --border: #e8eaed;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
  --shadow-hover: 0 4px 12px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.06);
  --safe-top: env(safe-area-inset-top);
  --safe-bottom: env(safe-area-inset-bottom);
  --transition: 0.2s ease;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html {
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
  scroll-behavior: smooth;
}
body {
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
  min-height: -webkit-fill-available;
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
  -webkit-tap-highlight-color: transparent;
  -webkit-overflow-scrolling: touch;
  letter-spacing: -0.01em;
}
.header {
  background: var(--surface);
  padding: 1.5rem 1.25rem;
  padding-top: calc(1.5rem + var(--safe-top));
  border-bottom: 1px solid var(--border);
  text-align: center;
  box-shadow: 0 1px 0 rgba(0,0,0,0.04);
}
.header h1 { font-size: 1.5rem; letter-spacing: -0.02em; }
.header h1 .brand { color: #c00; font-weight: 700; }
.header .tagline { font-size: 0.9rem; color: var(--text-dim); margin-top: 0.35rem; }
.container { max-width: 720px; margin: 0 auto; padding: 1rem max(1rem, env(safe-area-inset-left)); padding-right: max(1rem, env(safe-area-inset-right)); }
.grade-cards { display: grid; gap: 1rem; margin-bottom: 2rem; }
.grade-card {
  display: block;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.35rem 1.5rem;
  min-height: 3.5rem;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
  -webkit-tap-highlight-color: transparent;
}
.grade-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}
.grade-card:active { transform: scale(0.99); }
.grade-card:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.grade-card[data-level="elementary"]:hover { border-color: var(--elementary); }
.grade-card[data-level="middle"]:hover { border-color: var(--middle); }
.grade-card[data-level="high"]:hover { border-color: var(--high); }
.grade-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.3rem 0.65rem;
  border-radius: 6px;
  margin-bottom: 0.75rem;
  letter-spacing: 0.02em;
}
.grade-card[data-level="elementary"] .grade-badge { background: rgba(21,128,61,0.12); color: var(--elementary); }
.grade-card[data-level="middle"] .grade-badge { background: rgba(180,83,9,0.12); color: var(--middle); }
.grade-card[data-level="high"] .grade-badge { background: var(--accent-soft); color: var(--high); }
.grade-card h2 { font-size: 1.15rem; margin-bottom: 0.35rem; font-weight: 600; }
.grade-card p { font-size: 0.9rem; color: var(--text-dim); line-height: 1.5; }
.btn {
  display: inline-block;
  padding: 0.875rem 1.5rem;
  min-height: 2.75rem;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  text-align: center;
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn-primary {
  background: var(--accent);
  color: #fff;
  width: 100%;
  max-width: 320px;
  margin: 0 auto;
  box-shadow: 0 2px 8px rgba(29, 78, 216, 0.25);
}
.btn-primary:hover { background: var(--accent-hover); box-shadow: 0 4px 12px rgba(29, 78, 216, 0.3); }
.btn-primary:active { transform: scale(0.98); }
.quick-nav { text-align: center; }
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0;
  margin: -0.5rem 0 1rem;
  min-height: 2.75rem;
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.95rem;
  -webkit-tap-highlight-color: transparent;
}
.back-link:hover { color: var(--accent); }
.back-link:active { opacity: 0.8; }
.back-link:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
/* 목록 페이지: 초등/중등/고등 한 화면에, 박스 이쁘게 */
.list-page {
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.list-page .header { flex-shrink: 0; }
.list-page .footer { flex-shrink: 0; }
.list-page main.container {
  flex: 1;
  min-height: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  padding-bottom: 0;
}
.list-main {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}
.list-page .back-link { margin-bottom: 0.3rem; flex-shrink: 0; }
.list-page .issue-selector { padding: 0.2rem 0; margin-bottom: 0.3rem; flex-shrink: 0; }
.list-section--single {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.list-section--single .list-section-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--border);
  letter-spacing: -0.02em;
  flex-shrink: 0;
}
.list-section--single .article-grid {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem 0.75rem;
  align-content: stretch;
}
.list-section--single .article-grid--elementary { grid-template-rows: repeat(3, 1fr); }
.list-section--single .article-grid--middle   { grid-template-rows: repeat(4, 1fr); }
.list-section--single .article-grid--high    { grid-template-rows: repeat(6, 1fr); }
.list-section--single .article-card {
  height: 100%;
  min-height: 0;
  display: flex;
  flex-direction: column;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: box-shadow var(--transition), transform var(--transition);
}
.list-section--single .article-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.list-section--single .article-card-thumb {
  flex: 1;
  min-height: 0;
  background: var(--border);
  overflow: hidden;
}
.list-section--single .article-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.list-section--single .article-card-body {
  flex-shrink: 0;
  padding: 0.5rem 0.6rem;
}
.list-section--single .article-card-issue {
  font-size: 0.65rem;
  color: var(--text-dim);
  margin-bottom: 0.15rem;
}
.list-section--single .article-card-title {
  font-size: 0.82rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.15rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.list-section--single .article-card-byline {
  font-size: 0.68rem;
  color: var(--text-dim);
}
.list-header { margin-bottom: 1.25rem; }
.list-header h1 { font-size: 1.35rem; font-weight: 700; letter-spacing: -0.02em; }
.list-header .level-badge {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.25rem 0.55rem;
  border-radius: 6px;
  margin-top: 0.5rem;
  font-weight: 600;
}
.list-header .level-badge.elementary { background: rgba(21,128,61,0.12); color: var(--elementary); }
.list-header .level-badge.middle { background: rgba(180,83,9,0.12); color: var(--middle); }
.list-header .level-badge.high { background: var(--accent-soft); color: var(--high); }
.issue-selector {
  padding: 0.5rem 0;
  margin-bottom: 1rem;
}
.issue-selector label { font-size: 0.85rem; color: var(--text-dim); margin-right: 0.5rem; font-weight: 500; }
.issue-selector select {
  font-family: inherit;
  font-size: 0.9rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: border-color var(--transition);
}
.issue-selector select:focus { outline: none; border-color: var(--accent); }
.level-nav {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}
.level-nav-link {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.level-nav-link:hover {
  background: var(--surface);
  border-color: var(--text-dim);
}
.level-nav-link--elementary:hover, .level-nav-link--elementary:focus-visible { border-color: var(--elementary); color: var(--elementary); }
.level-nav-link--middle:hover, .level-nav-link--middle:focus-visible { border-color: var(--middle); color: var(--middle); }
.level-nav-link--high:hover, .level-nav-link--high:focus-visible { border-color: var(--high); color: var(--high); }
/* 한 페이지에 꽉 차게: 초등 5개 / 중등 8개 / 고등 12개 */
.list-section {
  display: flex;
  flex-direction: column;
  min-height: 0;
  box-sizing: border-box;
}
.list-section:last-child { padding-bottom: 0; }
.list-section-title {
  flex-shrink: 0;
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--border);
  letter-spacing: -0.02em;
}
.list-section-title--elementary { border-bottom-color: var(--elementary); color: var(--elementary); }
.list-section-title--middle { border-bottom-color: var(--middle); color: var(--middle); }
.list-section-title--high { border-bottom-color: var(--high); color: var(--high); }
/* 기사 그리드: 남는 높이를 채우고 행 수만큼 균등 분할 */
.article-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem 0.75rem;
  list-style: none;
  flex: 1;
  min-height: 0;
  align-content: stretch;
}
.article-grid--elementary { grid-template-rows: repeat(3, 1fr); }
.article-grid--middle   { grid-template-rows: repeat(4, 1fr); }
.article-grid--high     { grid-template-rows: repeat(6, 1fr); }
.article-card {
  display: flex;
  flex-direction: column;
  min-height: 0;
  height: 100%;
  background: var(--surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  text-decoration: none;
  color: var(--text);
  transition: box-shadow var(--transition), transform var(--transition);
  -webkit-tap-highlight-color: transparent;
}
.article-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.article-card:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.article-card-thumb {
  flex: 1;
  min-height: 0;
  width: 100%;
  background: var(--border);
  overflow: hidden;
}
.article-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.article-card-thumb--empty {
  background: linear-gradient(135deg, var(--border) 0%, #e0e2e5 100%);
}
.article-card-body {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  padding: 0.4rem 0.5rem 0.5rem;
  min-height: 0;
}
.article-card-issue {
  font-size: 0.6rem;
  color: var(--text-dim);
  margin-bottom: 0.2rem;
  letter-spacing: 0.02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.article-card-title {
  font-size: 0.8rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.2rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  letter-spacing: -0.01em;
}
.article-card-byline {
  font-size: 0.65rem;
  color: var(--text-dim);
}
/* 고등: 반은 이미지, 반은 제목(가로 배치) */
.article-grid--middle .article-card,
.article-grid--high .article-card {
  flex-direction: row;
}
.article-grid--middle .article-card-thumb,
.article-grid--high .article-card-thumb {
  flex: 0 0 50%;
  width: 50%;
  min-height: 0;
}
.article-grid--middle .article-card-body,
.article-grid--high .article-card-body {
  flex: 1;
  min-width: 0;
  justify-content: center;
  padding: 0.5rem 0.6rem;
}
.article-grid--middle .article-card-title,
.article-grid--high .article-card-title {
  -webkit-line-clamp: 3;
}
@media (max-width: 480px) {
  .article-grid { grid-template-columns: 1fr; }
  .article-grid--elementary { grid-template-rows: repeat(5, 1fr); }
  .article-grid--middle   { grid-template-rows: repeat(8, 1fr); }
  .article-grid--high     { grid-template-rows: repeat(12, 1fr); }
  .article-card-title { -webkit-line-clamp: 2; }
  .article-grid--middle .article-card,
  .article-grid--high .article-card { flex-direction: row; }
  .article-grid--middle .article-card-thumb,
  .article-grid--high .article-card-thumb { flex: 0 0 50%; width: 50%; }
  .article-grid--middle .article-card-title,
  .article-grid--high .article-card-title { -webkit-line-clamp: 2; }
}
.list-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.list-header-link {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}
.list-header-link:hover { background: var(--accent-soft); color: var(--accent-hover); }
.list-header-link .arrow { font-size: 1em; }
.article-list { list-style: none; }
.article-item {
  background: var(--surface);
  border-radius: var(--radius);
  margin-bottom: 0.75rem;
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}
.article-item:hover { box-shadow: var(--shadow-hover); }
.article-item a {
  display: flex;
  align-items: center;
  padding: 1rem max(1rem, env(safe-area-inset-right));
  padding-left: max(1rem, env(safe-area-inset-left));
  min-height: 3.25rem;
  text-decoration: none;
  color: var(--text);
  gap: 0.75rem;
  -webkit-tap-highlight-color: transparent;
  transition: background var(--transition);
}
.article-item a:hover { background: var(--bg); }
.article-item a:active { background: var(--border); }
.article-item a:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }
.article-item .num { font-size: 0.8rem; color: var(--text-dim); min-width: 2.5rem; font-weight: 500; }
.article-item .title { font-weight: 500; flex: 1; min-width: 0; font-size: 0.95rem; line-height: 1.45; }
.article-item .level-tag { font-size: 0.7rem; padding: 0.25rem 0.45rem; border-radius: 6px; background: var(--bg); color: var(--text-dim); font-weight: 500; }
.article-img-wrap {
  width: 100%;
  aspect-ratio: 16/10;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--border);
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow);
}
.article-img-wrap img { width: 100%; height: 100%; object-fit: cover; display: block; }
.article-detail .meta { font-size: 0.85rem; color: var(--text-dim); margin-bottom: 1rem; }
.article-detail .level-tag { margin-right: 0.5rem; }
.article-detail h1 {
  font-size: clamp(1.2rem, 4.5vw, 1.4rem);
  margin-bottom: 1rem;
  line-height: 1.4;
  word-break: keep-all;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.article-detail .body {
  background: var(--surface);
  padding: max(1.35rem, env(safe-area-inset-left));
  padding-right: max(1.35rem, env(safe-area-inset-right));
  border-radius: var(--radius);
  line-height: 1.9;
  font-size: clamp(0.9375rem, 2.5vw, 1rem);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.article-detail .body p { margin-bottom: 1rem; }
.article-detail .body p:last-child { margin-bottom: 0; }

/* 기사 아래 핵심 키워드 (키워드 : 뜻 / 예문 : ~) */
.article-keywords {
  margin-top: 1.75rem;
  padding: 1.25rem;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.keywords-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent);
  letter-spacing: -0.01em;
}
.keywords-list {
  margin: 0;
  padding: 0;
  list-style: none;
}
.keyword-item {
  margin-bottom: 0.6rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
}
.keyword-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}
.keyword-line {
  margin: 0 0 0.25rem 0;
  font-size: 0.9rem;
  line-height: 1.45;
}
.keyword-word {
  font-weight: 700;
  color: var(--accent);
  font-size: 0.95rem;
}
.keyword-meaning {
  color: var(--text);
  font-weight: 400;
}
.keyword-example-line {
  margin: 0;
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.45;
}
.keyword-example {
  display: inline;
}
.keyword-example-line .keyword-example {
  display: inline-block;
  margin-left: 0.15rem;
  padding: 0.25rem 0.4rem;
  background: var(--bg);
  border-radius: 6px;
  border-left: 3px solid var(--accent);
  color: var(--text);
  font-size: 0.85rem;
}

/* 기사 하단 이전·다음 기사 */
.article-nav {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  gap: 1rem;
  margin-top: 1.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}
.article-nav-link {
  flex: 1;
  max-width: 48%;
  display: flex;
  flex-direction: column;
  padding: 0.85rem 1rem;
  background: var(--surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  text-decoration: none;
  color: var(--text);
  transition: border-color var(--transition), background var(--transition), box-shadow var(--transition);
  -webkit-tap-highlight-color: transparent;
  min-height: 2.75rem;
  justify-content: center;
  box-shadow: var(--shadow);
}
.article-nav-link:hover { border-color: var(--accent); background: var(--accent-soft); box-shadow: var(--shadow-hover); }
.article-nav-link:active { opacity: 0.95; }
.article-nav-link:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.article-nav-prev { text-align: left; }
.article-nav-next { text-align: right; }
.article-nav-label {
  font-size: 0.78rem;
  color: var(--text-dim);
  margin-bottom: 0.3rem;
  font-weight: 500;
}
.article-nav-next .article-nav-label { margin-bottom: 0.3rem; margin-top: 0; }
.article-nav-title {
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1.4;
  word-break: keep-all;
}
.article-nav.article-nav-prev-only .article-nav-prev { max-width: 100%; }
.article-nav.article-nav-next-only .article-nav-next { max-width: 100%; }

.article-detail .locked-msg {
  background: #fef2f2;
  color: #b91c1c;
  padding: 1rem;
  border-radius: var(--radius);
  margin-top: 1rem;
  font-size: 0.9rem;
}
.article-detail .locked-msg a { color: var(--accent); }
/* 구독 플랜 페이지: 박스만 이쁘게, 스크롤 자유 */
.pricing-page .pricing-header p { display: block; }
.pricing-page .plans {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}
.pricing-page .plan-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.25rem 1.25rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.pricing-page .plan-card:hover { box-shadow: var(--shadow-hover); }
.pricing-page .plan-card.recommended {
  border-color: var(--accent);
  position: relative;
  box-shadow: 0 0 0 1px var(--accent), var(--shadow);
}
.pricing-page .plan-card.recommended::before {
  content: '추천';
  position: absolute;
  top: -10px;
  left: 1rem;
  background: var(--accent);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
  letter-spacing: 0.02em;
}
.pricing-page .plan-card h3 { font-size: 1.1rem; margin-bottom: 0.5rem; font-weight: 600; }
.pricing-page .plan-card .price { font-size: 1.4rem; font-weight: 700; color: var(--accent); }
.pricing-page .plan-card .price-note { font-size: 0.85rem; color: var(--text-dim); margin-top: 0.3rem; }
.pricing-page .plan-card .features {
  margin: 1rem 0;
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.5;
  padding-left: 1.1rem;
}
.pricing-page .plan-card .features li { margin: 0.35rem 0; }
.pricing-page .plan-card .btn {
  width: 100%;
  margin-top: 0.75rem;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
}
.pricing-header { text-align: center; margin-bottom: 2rem; }
.pricing-header h1 { font-size: 1.5rem; font-weight: 700; letter-spacing: -0.02em; }
.pricing-header p { color: var(--text-dim); margin-top: 0.5rem; font-size: 0.95rem; }
.plans { display: grid; gap: 1.25rem; margin-bottom: 2rem; }
.plan-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.5rem;
  border: 1px solid var(--border);
  transition: border-color var(--transition), box-shadow var(--transition);
  box-shadow: var(--shadow);
}
.plan-card:hover { box-shadow: var(--shadow-hover); }
.plan-card.recommended {
  border-color: var(--accent);
  position: relative;
  box-shadow: 0 0 0 1px var(--accent), var(--shadow);
}
.plan-card.recommended::before {
  content: '추천';
  position: absolute;
  top: -10px;
  left: 1rem;
  background: var(--accent);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
  letter-spacing: 0.02em;
}
.plan-card h3 { font-size: 1.1rem; margin-bottom: 0.5rem; font-weight: 600; }
.plan-card .price { font-size: 1.5rem; font-weight: 700; color: var(--accent); }
.plan-card .price-note { font-size: 0.85rem; color: var(--text-dim); margin-top: 0.3rem; }
.plan-card .features { margin: 1rem 0; font-size: 0.9rem; color: var(--text-dim); line-height: 1.55; }
.plan-card .features li { margin: 0.4rem 0; }
.plan-card .btn { width: 100%; margin-top: 0.6rem; }
.payment-box {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.payment-box h2 { font-size: 1.1rem; margin-bottom: 1rem; font-weight: 600; }
.payment-summary { font-size: 0.95rem; color: var(--text-dim); line-height: 1.6; }
.payment-summary strong { color: var(--text); }
#toss-btn { margin-top: 1rem; width: 100%; padding: 1rem; font-size: 1rem; }
.result-page { text-align: center; padding: 2rem 1rem; }
.result-page h1 { font-size: 1.5rem; margin-bottom: 1rem; font-weight: 700; }
.result-page.success h1 { color: var(--elementary); }
.result-page.fail h1 { color: #b91c1c; }
.result-page .detail {
  background: var(--surface);
  padding: 1.25rem;
  border-radius: var(--radius);
  text-align: left;
  max-width: 400px;
  margin: 1rem auto;
  font-size: 0.9rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.result-page .detail dt { color: var(--text-dim); margin-top: 0.5rem; }
.result-page .detail dd { margin-left: 0; font-weight: 500; }
.result-page .btn { margin-top: 1rem; min-height: 2.75rem; padding: 0.875rem 1.5rem; }
.result-page .btn + .btn { margin-top: 0.75rem; }
.footer {
  text-align: center;
  padding: 1.35rem 1rem;
  padding-bottom: max(1.35rem, env(safe-area-inset-bottom));
  font-size: 0.85rem;
  color: var(--text-dim);
  border-top: 1px solid var(--border);
  margin-top: auto;
  background: var(--surface);
}

/* 모바일: 좁은 화면 보강 */
@media (max-width: 480px) {
  .header { padding-left: max(1rem, env(safe-area-inset-left)); padding-right: max(1rem, env(safe-area-inset-right)); }
  .header h1 { font-size: 1.35rem; }
  .header .tagline { font-size: 0.85rem; }
  .container { padding-top: 1rem; padding-bottom: 1rem; }
  .grade-cards { gap: 0.75rem; margin-bottom: 1.5rem; }
  .grade-card { padding: 1.25rem 1rem; }
  .grade-card h2 { font-size: 1.1rem; }
  .list-header h1 { font-size: 1.2rem; }
  .plan-card { padding: 1.25rem 1rem; }
  .plan-card .price { font-size: 1.35rem; }
  .pricing-page .plans { gap: 0.75rem; }
  .pricing-page .plan-card { padding: 1rem; }
  .list-section--single .article-grid { grid-template-columns: 1fr; }
  .list-section--single .article-grid--elementary { grid-template-rows: repeat(5, 1fr); }
  .list-section--single .article-grid--middle   { grid-template-rows: repeat(8, 1fr); }
  .list-section--single .article-grid--high     { grid-template-rows: repeat(12, 1fr); }
  .payment-box { padding: 1.25rem 1rem; }
  .result-page { padding: 1.5rem 1rem; }
  .result-page .detail { margin-left: 1rem; margin-right: 1rem; }
}

/* 터치 기기: 호버 대신 포커스/활성 스타일 */
@media (hover: none) {
  .grade-card:hover { transform: none; }
  .grade-card:active { transform: scale(0.98); border-color: var(--elementary); }
  .grade-card[data-level="middle"]:active { border-color: var(--middle); }
  .grade-card[data-level="high"]:active { border-color: var(--high); }
}

/* 접근성: 동작 축소 선호 시 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}